October 5, 2010

Vaccines For Smallpox And Anthrax Combined

by ssavage

US government researchers announced Monday they have combined smallpox and anthrax vaccines into one vaccine, improving them and making them safer, faster-acting and more effective in case of a biological attack.

"Although licensed vaccines are available for both smallpox and anthrax, because of inadequacies associated with each of these vaccines, serious concerns remain as to the deployability of these vaccines, especially in the aftermath of a bioterror attack involving these pathogens," wrote Liyanage Perera of the US National Cancer Institute and colleagues.

The researchers said the new dual vaccine can be freeze-dried, stockpiled and quickly delivered when it is needed.

Perera and colleagues at the US Food and Drug Administration along with small biotech firm JDM Technologies in Maryland, had reported earlier the improvements to Wyeth's DryVax vaccine against smallpox.

Smallpox was wiped out in 1979 after a persistent global vaccination campaign. But some experts believe that the former Soviet Union had developed smallpox viruses into biological weapons and that they could have made their way into enemy hands.

Anthrax can also be developed into a deadly weapon.

In the weeks and months following the 9-11 attacks on the World Trade Center and the Pentagon, five people died and more than a dozen were injured when someone -- or some group -- mailed letters that had carried the deadly anthrax spores. A government researcher at Fort Detrick in Maryland was the chief suspect but he committed suicide before he could be charged.

The current vaccine for smallpox has potentially deadly side-effects. It is not used in the general population and people born after 1972 are very unlikely to have been vaccinated.

The current anthrax vaccine does not work well and several companies are working on alternative solutions, some with multimillion-dollar contracts from the US government. Both vaccines are given to the US military.

Perera and colleagues adjusted the current smallpox vaccine by adding an immune system compound called interleukin-15, and genetically altered the virus used to make it. They added one protein from the anthrax bacteria to make the dual vaccine.

The new dual vaccine was tested in rabbits and mice and the test results suggest the combined vaccine would protect better than either of the older ones alone, they said.

Antibiotics made for anthrax can protect people from the deadly germ, but only if they are taken quickly. The spores can live in the body for weeks and months before becoming active.

"We believe our dual vaccine, Wyeth/IL-15/PA, which is effective against two of the most deadly pathogens, will help consolidate and simplify our national bioterror counter efforts by streamlining the manufacture, stockpiling, and swift deployment of such vaccines should the need arise," Perera and colleagues concluded.

The vaccine requires federal approval before it could be developed for use in people. The researchers were not immediately available for comment on when they would apply for approval.

The researchers wrote about their work in the Proceedings of the National Academy of Sciences.